This is Steven Salzberg's blog on genomics, pseudoscience, medical breakthroughs, higher education, and other topics, including skepticism about unscientific medical practices. Here's where I can say what I really think about abuses and distortions of science, wherever I see them.

T. rex peptides now available to public

I'm pleased to follow-up my August 22 post with a note that John Asara has responded to the calls for him and his colleagues to release the spectra from their study that reported the identification of Tyrannosaurus rex collagen protein isolated from a 68-million-year-old fossil. Pavel Pevzner, Tom Kaye, Mike Buckley, and others have all called this data into question, arguing in 3 separate papers that the protein fragments represent modern contaminents or statistical artifacts, rather than original T. rex proteins.

Pevzner argued forcefully that the only way to validate the claim was to have independent scientists look at all the spectra generated in the original experiment. Asara has now agreed, and has released all the spectra at the PRIDE database. I encourage those with expertise in the analysis of mass spec data to take a look. It will likely take some time for this analysis, but I will follow the developments and report them here.

I should add that although I remain skeptical that original T. rex proteins - even fragments - survived for 68 million years, I find it very plausible that such proteins would indeed be similar to those from modern birds. But the issue of whether proteins could survive for so long is a separate question from their evolutionary relatedness to modern species.

2 comments:

Hi,Has anybody had a chance to analyze the T. rex raw MS/MS data from teh PRIDE database? I am very eager to hear about your results. However, according to the PRIDE database stipulations, please do not comment on anything other than collagen that you think may be endogenous to ancient bone material (bacterial peptides and other common contaminants don't fall into this category). I am most interested to learn if you find collagen statistically significant from the relaeased 48,216 spectra. If so, what are the actual collagen sequences that you have interpreted?Thanks for the help,John

hi John (and others),I've heard just this week that several other scientists are actively working on their analyses of the data that you released to the PRIDE database. I'm not sure when they will be ready to discuss their findings - or if they will post anything here. I guess we just have to be patient. I will post a notice here if I learn of any public results elsewhere.